Peptide encoding and dual-function sRNAs in Bacillus subtilis

枯草芽孢杆菌是最重要的非致病性革兰氏阳性模式生物，其可以将蛋白质大量分泌到生长培养基中，因此，用于许多酶如淀粉酶和蛋白酶的工业生产。与革兰氏阴性模式生物E. coli，B.枯草芽孢杆菌是天然感受态的，并且可以响应于营养胁迫形成孢子以在极端条件下存活。此外，由于它与致病杆菌有关，例如B.炭疽杆菌或B.本研究的主要目的是从蜡样芽孢杆菌（B. cereus）中筛选出编码新的多肽和具有双重功能的sRNAs。枯草芽孢杆菌，并进一步在它们的表达、靶和生物学作用方面表征它们。本课题的主要工作包括以下三个方面：1）研究了短链mRNAs和双功能sRNAs编码的小肽的生物学功能，并对短链mRNAs和双功能sRNAs编码的小肽的生物学功能进行了初步的研究。 不同生长和胁迫条件下四种肽编码sRNAs的表达谱和表达调控分析。潜在转录调节因子的鉴定2） 使用C-和N-末端标记肽的共洗脱和共免疫沉淀试验以及野生型、敲除和过表达菌株的转录组学和肽组学来搜索肽靶点。阐明这些肽的生物学作用。第三章 使用转录组学和体外与体内技术的组合研究这些spRNAs的额外碱基配对功能

Bacillus subtilis is the most important non-pathogenic Gram-positive model organism that can secrete proteins in large quantities into the growth medium and is, therefore, used for the industrial production of a number of enzymes such as amylases and proteases. In contrast to the Gram- negative model organism E. coli, B. subtilis is naturally competent and can sporulate in response to nutritional stress to survive extreme conditions. Moreover, since it is related to pathogenic Bacilli as e.g. B. anthracis or B. cereus, it can be used as a model organism for the regulation of metabolic responses or stress of such pathogenic bacteria as well.The major aims of this project are to identify novel peptide encoding and dual-function sRNAs in B. subtilis and to further characterize them in terms of their expression, targets and biological role. We expect to discover novel functions for small peptides encoded by either short mRNAs or new dual function sRNAs.The experimental work will be divided into the following three parts:1) Analysis of expression profiles and expression control of four peptide encoding sRNAs under different growth and stress conditions. Identification of potential transcriptional regulators.2) Search for peptide targets using co-elution and co-immunoprecipitation assays with C- and N-terminally tagged peptides and transcriptomics and peptidomics with wild-type, knockout- and overexpression strains. Elucidation of the biological role of these peptides. 3) Investigation of additional base-pairing functions of these spRNAs using transcriptomics and a combination of in vitro and in vivo techniques